1. Field of the Invention
The present invention relates to a multilayer film-coated member fabricated by forming a multilayer film on a substrate for abrasion-resistant members for cutting tools, molds and combustion engines or for members requiring heat resistance and abrasion resistance for airplanes, ground turbines, engines, gaskets, gears, pistons and others, and relates to a method for producing it.
2. Background Art
For the purpose of improving the heat resistance and abrasion resistance of coating films, development of various coating films is being promoted. With reference to typical cases of Patent References 1 to 3, described is one example of a process of development of coating films essentially for the purpose of improving the heat resistance and abrasion resistance of coating films. For the purpose of improving the heat resistance, many trials to coat heat-resistant materials have heretofore been made. For example, in Patent Reference 1, proposed is a coating film with oxides of Y and Si dispersed in a glassy matrix comprising SiO2 and B2O3. This is an invention of a heat-resistant coating film with Si. However, the abrasion resistance of the film is not improved, and therefore it is difficult to apply the film to tools and slide members. In Patent Reference 2, proposed is a (TiAl(SiC))N coating film formed by the use of a target material with SiC powder having excellent heat resistance and abrasion resistance, for the purpose of improving the heat resistance and the abrasion resistance of TiAlN coating films widely used in the market. Accordingly, as compared with a TiAlN coating film, the (TiAl(SiC))N coating film has improved heat resistance and abrasion resistance, but since the base of the film is TiAlN, the effect of the improvement is limited. For further improving the abrasion resistance and the heat resistance, the present applicant has proposed a Si(BCN)-based coating film described in Patent Reference 3. Accordingly, the abrasion resistance and the heat resistance of coating films for use for cutting tools and abrasion-resistant members have been greatly improved.
Patent Reference 1: JP-A 2002-87896
Patent Reference 2: Japanese Patent 3370291
Patent Reference 3: JP-A 2007-126714
For example, in the field of cutting work, the objects to be cut are being more difficult to cut and the working time is being much shortened for more rapid cutting speed and more rapid feeding of objects. With these requirements, cutting tools are forced to be exposed too much severer working environments than before. Given the situation, the applicant of the present invention has proposed a coating film having excellent abrasion resistance and heat resistance as in Patent Reference 3. In one application example of the coated member of the invention of Patent Reference 3, a cutting tool with the coating film was tested and evaluated for its cutting capability, which confirmed more excellent performance of the tool over conventional cases. However, in order that the coated member could be applicable to further severer cutting conditions, it has been known that the adhesion strength of the coating film must be more improved.